1. Field of the Invention
The present invention relates to a data processing apparatus, a data processing method and an image forming apparatus which can be used as a MFP (Multi Function Product) equipped with multiple functions such as a copying function, a scanner function and a facsimile function.
In the following description, a facsimile and an internet-facsimile will be abbreviated as “FAX” and “IFAX” respectively.
2. Description of Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
To realize the multiple functions, a MFP as mentioned above is equipped with a plurality of input portions such as a receiving portion for receiving print jobs sent from an external apparatus such as a personal computer (hereinafter referred to as “PC”) via a network, a receiving portion for receiving FAX jobs sent from an external apparatus such as a FAX machine via a communication line network and an original reading portion for reading an original.
Further equipped are a printer portion for printing an image data read by the original reading portion or a print data from the external apparatus, a working memory for spreading a data-to-be-outputted inputted from each input means and a file memory for storing the once inputted data for second and subsequent outputs.
In order to minimize the storage capacity of the data to be stored in the file memory, in general, a compressing/expanding device for compressing or expanding data is equipped. The data spread on the working memory is transferred to the compressing/expanding device to be compressed, and the compressed data is stored in the file memory.
In such a MFP, in cases where a print job is inputted from an external apparatus or the like, the print data included in the inputted job is spread on the working memory and the spread data is transferred to the printing portion for printing. Simultaneously, the data is transferred to the compressing/expanding device to be compressed and then stored in the file memory. In cases where a second one is printed, the compressed data stored in the file memory is expanded by the compressing/expanding device and transferred to the working memory again. Then, the data is transferred to the print portion for printing.
In the meantime, there is a possibility that a copy job for reading an original at an original reading portion and then transmitting the read original data to an external apparatus may sometimes be inputted during the print job processing. In this case, since the print job is being executed, i.e., the compressing/expanding device is being used, the initiation of the copy job will be delayed until the compressing/expanding device is released.
Furthermore, even in cases where this print job is a job such as a confidential print job which is not required to be printed without delay, the subsequent copy job cannot be executed until the completion of the current print job, which causes the user of the copy job frustration.
U.S. Pat. No. 6,381,031 discloses a technique in which the assignment of the compression/expansion operation to be allotted to the compressing/expanding devices connected in parallel is changed depending on the quantity of the data-to-be-outputted. For example, the U.S. Patent discloses that, in cases where the code data is read out from the file memory while thinning out or only the code data of even-numbered pages is read out, since the quantity of data to be stored in the file memory is greater than that of the image data to be read out, the number of the compressing/expanding devices for executing the compression operation is increased and that for executing the expansion operation is decreased. Furthermore, the U.S. Patent discloses that, in the case of a sort copy, all of the compressing/expanding devices are used to compress the data of the first original, half of them are used to compress and expand the data of the second and subsequent originals, and all of them are used to expand the compressed data after the completion for storing the data.
According to the technique disclosed in the aforementioned U.S. Patent, although it discloses an efficient operation of the compressing/expanding devices, it fails to disclose such technical concept that the initiation of the subsequent job is expedited depending on whether the previous job is not required to be outputted without delay. Thus, it was not enough to solve the aforementioned problems.
It may be considered that the compressing/expanding devices are classified into compressing/expanding devices to be exclusively used for compressing data and compressing/expanding devices to be exclusively used for expanding data, wherein the data compression for the previous job is executed by the compressing/expanding devices to be exclusively used for compressing data and thereafter the data compression for the subsequent job is also executed by the same compressing/expanding devices to thereby expedite the initiation of the subsequent job.
In this case, however, even in cases where the previous job is required to be outputted without delay, the data of the previous job is compressed or expanded always by the small number of compressing/expanding devices, resulting in a deteriorated reading speed of the job or a deteriorated productivity of the output. Furthermore, during the compressing/expanding processing of the data of the previous job, the initiation of the subsequent job cannot be executed.
Furthermore, it may be considered to change the assignment of the compressing/expanding devices for the previous job after the input of the subsequent job. In this case, however, it takes a time from the input of the subsequent job to the execution of the subsequent job due to the assignment change processing.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention. Indeed, certain features of the invention may be capable of overcoming certain disadvantages, while still retaining some or all of the features, embodiments, methods, and apparatus disclosed therein.